Illuminating device.



J. LAFITTE. ILLUMINATING DEVICE. APPLICATION um MAY 13, 1912.

1,073,147. Patented Sept. 16, 1913.

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T 0 all whom it may concern.-

' 7 Be it known that I, JOACHI'M Larirrn,

a citizen of the French Republic, residing at Biarritz, France, have invented certain new and useful Improvements in Illuminating Devices, of which the following is a specification.

This invention relates to apparatus by means cit which it'is possible to obtain in an economic manner a very considerable increase in theefiiciency of a luminous source.

According to this invention the protective casing of a single luminous source, comprises reflecting strips alternating with transparent strips, the whole of the source and of the casing being given synchronous movements of rotation at a suitable speed around the axis of the luminous source, so

that during the rotation of the apparatus, the relative positions of the luminous source, reflecting strips and transparent strips, remains constant thereby insuring the maximum efficiency as regards, the light, while insuring difiiusion in space and continuity of the luminous sheet emitted.

This invention is generally applicable to any source of light, but more particularly to electric incandescent or are lamps.

an elevation of a table lamp and Figs. 3 and L are diagrammatic horizontal sections of two constructions of the globes or bulbs.

According to this invention, the circular casing a surrounding any source of light, for example such as a globe or bulb is divided into reflecting strips c alternating with transparent strips Z), the number of strips of each series being preferably an odd one, in order that the rays reflected by one of the series can pass without being intercepted, through the elements of the otherseries.

The whole of the lamp with its protective casing a, is given a movement of rotation about its longitudinal axis, at a suitable speed, thesaid movement being transmitted by any suitable driving mechanism arranged either close to, or at a distance from, the lamp.

Owing to the synchronous rotation of the source f and of the suitably distributed recircular advance of the reflected beams, the

' s ecification of Letters Patent. P t t d 1; 15 19:13

Application filed May 13, 1912. Serial 1N 0. 696,948.

- points of emission always remaining in the same position relatively to the points of reflection of the reflecting-surfaces. By giving the movement of rotation a suitable speed, su'fliciently frequent periods are obtained for producing a favorable excitation of the eye, producing the impression of a continuous and permanent circular luminous reflection.

The reflecting and transparent surfaces can be of any shape, plain or striped, hollow or projecting, and can be combined to-- gether tor producing any desired kind of divergent "or convergent racl1a'tion.

As will be seen from Fig. 1, the bulb of an electric lamp of ovoid shape is divided intoalternately reflecting and transparent strips, and the whole of the lamp is suspended from the spindle of the armature ot eleotricmotor (Z or the kind used for fans, the said spindle being secured to a ceiling bracket or to a wall bracket, or, if necessary, the lamps can be suspended from the end of along cable. The electricconnectio ns diagrammatically indicated, comprise a resistance a" for regulating the speed of the motor, a washer g of insulatingma terIal-,brush holders, as well as a device for regulating the central position of the lamp In the accompanying drawing given by way of example, Figure 1 is an elevation; of a suspended lamp with a bulb; 2 is- 7: Z and sending it into the lamp and after ward returning it to the line.

In the modified construction shown in Fig. 2, the bulb a of the lamp is of spherical shape and has the same arrangement of reflecting and transparent strips of a more or less large number, as the device shown in Fig. 1, and is secured to the spindle of the armature of an electric motor (Z, the outer casing of which constitutes a leg or stand supporting the whole of the apparatus. The current is supplied by means of two insulated and superposed metal rings on n with which engage the brushes 0 79 connected to the electric circuit. The adjustment of the speed of the motor is effected by means of a brake which can act automatically or not,

and can be applied to the two devices illustrated, or the blades 3 of a fan, can operate through the resistance of the air.

In these two constructions, the bulbs can be of spherical, ovoid or elliptical as in dotted outline e e in Fig. 2 or other desired shape.

The reflecting portions can be made either in one piece with the bulbs, or arranged in the shape of separate independent segments. This apparatus for increasing the efliciency of a source of light has great advantages over the apparatus with a fixed lu minous source and movable reflectors, that is to say, with reflectors rotating about the said source. This device is obviously of simpler construction, and at the same time constitutes a considerable improvement both in the optical result, and as regards the facility of application, as it is suitable for all purposes, even inside buildings. On the other hand, the luminous source (whether derived from a filament, are or any other source of light), rotating together with the reflector system, produces a better movement and diffusion of the luminous rays and a diffusion in proportion to the amount of light generated by the filaments. Thus it enables a material economy of construction to be ettected, as the supports for the reflecf, tors and their fittings are not required.

What I claim as my invention and desire tosecure by Letters Patent is 1. An illuminating device comprising a source of light, a casing having an odd number of reflecting strips alternating with transparent strips, means for rotating the Copies of this patent may be obtained for casing and the source of light synchronously around the axis of said source, and an auto matic brake for regulating the speed of ro tation.

2. An illuminating device'comprising an electrical source of light constituted by the incandescent Wires of an incandescent electric'lamp, a casing having an odd number of reflecting strips alternatlng wlth transparent strips, means for rotating the casing and p the source of light synchronously around the axis of said source, for keeping the groups of wires in accordance with the reflecting strips and the transparent strips diametrically opposite and an automatic brake f0 regulating the speed of rotation. I r

3. An illuminating device comprising an electrical source of light constituted by an electric lamp with transparent globe, a case mg surrounding the said lamp, having an odd number of reflecting strips alternating name to this specification in the presence of two subscribing witnesses.

V JOAOHIM LAFITTE, Witnesses l ARTHUR SMITH, BENJAMIN MATTHEW.

five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

